An engine valve and a method of producing the engine valve are provided. The engine valve includes a shaft part and an umbrella part formed at one end of the shaft part. The engine valve opens and closes an intake port or an exhaust port of a combustion chamber of an internal combustion engine. Further, at least a portion of the engine valve that extends from the umbrella part to a position on the shaft part in a longitudinal direction thereof includes a valve body made of steel or nickel alloy, and a core member made of copper or copper alloy and provided inside the valve body.

An engine valve and a method of producing the engine valve are provided. The engine valve includes a shaft part and an umbrella part formed at one end of the shaft part. The engine valve opens and closes an intake port or an exhaust port of a combustion chamber of an internal combustion engine. Further, at least a portion of the engine valve that extends from the umbrella part to a position on the shaft part in a longitudinal direction thereof includes a valve body made of steel or nickel alloy, and a core member made of copper or copper alloy and provided inside the valve body.

A precision forming method of a high-efficiency and near-net hollow valve blank of an engine is provided, wherein the precision performing is realized by the cross wedge rolling mold, under the rolling the metal tubing for the valve deforms, with a middle part sunken and two ends elongating, the middle part forms a stem part of a hollow valve, the two ends form disk parts to be machined, and the connection sections between the disk parts and the stem part form neck parts having arced concave faces and a frustoconical lateral face in structure, achieving better consistency among the acquired hollow valve blanks. The disk part of each acquired hollow valve preformed blank is machined by the die-forging forming mold that is matched with the disk structure of the manufactured hollow valve, the hollow valve preformed blank is directly placed in the cavities of the die-forging forming mold for forging.

A precision forming method of a high-efficiency and near-net hollow valve blank of an engine is provided, wherein the precision performing is realized by the cross wedge rolling mold, under the rolling the metal tubing for the valve deforms, with a middle part sunken and two ends elongating, the middle part forms a stem part of a hollow valve, the two ends form disk parts to be machined, and the connection sections between the disk parts and the stem part form neck parts having arced concave faces and a frustoconical lateral face in structure, achieving better consistency among the acquired hollow valve blanks. The disk part of each acquired hollow valve preformed blank is machined by the die-forging forming mold that is matched with the disk structure of the manufactured hollow valve, the hollow valve preformed blank is directly placed in the cavities of the die-forging forming mold for forging.

Provided is a method for filling a stem-side hollow area of an engine valve with metallic sodium. The method includes injecting melted metallic sodium into a cylinder having a larger diameter than an inner diameter of the hollow area of the engine valve, forming a solidified metallic sodium rod having a substantially uniform structure in the cylinder, inserting the metallic sodium into the hollow area of the engine valve through a nozzle having a small diameter, and sealing the engine valve.

An exhaust valve for an internal combustion engine comprises a valve disc having a first side (14) and a second side (16), a valve stem extending from the first side of the valve disc, and an annular valve seat area (11) located at the first side of the valve disc. The annular valve seat area (11) is of a nickel-base alloy or a chromium-base alloy and has a valve seat surface. The annular valve seat area has at least a first annular portion (43) located in between two second annular portions (42). The first annular portion has lower hardness than the two second annular portions.

A method and a device for the production of an internally cooled inlet or outlet valve for internal combustion engines, together with the resultant valve includes provision of a workpiece, which has a cylindrical stem and a cylindrical hole and, extends in the axial direction from one end of the valve stem. The method includes reshaping the end of the valve stern by form rolling of the cylindrical stem to a smaller diameter, wherein a diameter of the cylindrical hole is reduced, wherein the cylindrical hole remains. The method further includes reshaping by form rolling the section of the workpiece that is adjacent to the valve stem to form the valve head.

A method and a device for the production of an internally cooled inlet or outlet valve for internal combustion engines, together with the resultant valve includes provision of a workpiece, which has a cylindrical stem and a cylindrical hole and, extends in the axial direction from one end of the valve stem. The method includes reshaping the end of the valve stern by form rolling of the cylindrical stem to a smaller diameter, wherein a diameter of the cylindrical hole is reduced, wherein the cylindrical hole remains. The method further includes reshaping by form rolling the section of the workpiece that is adjacent to the valve stem to form the valve head.

A front plate for a valve timing control device is produced which comprises a plate part that closes a front opening of a housing body to seal operation oil chambers in the housing body and a cylindrical part that is integral with and projected forward from an opened central portion of the plate part and after production of the front plate, an annular part of a front surface of the plate part near a root portion of the cylindrical part is pressed, by a press machine, toward a rear surface of the plate part against a supporting tool that intimately supports the rear surface of the plate part, so that the rear surface of the plate part has an improved flatness at an annular area surrounding the opening of the front plate thereby to increase a sealability between the plate part and the front opening of the housing body.

A front plate for a valve timing control device is produced which comprises a plate part that closes a front opening of a housing body to seal operation oil chambers in the housing body and a cylindrical part that is integral with and projected forward from an opened central portion of the plate part and after production of the front plate, an annular part of a front surface of the plate part near a root portion of the cylindrical part is pressed, by a press machine, toward a rear surface of the plate part against a supporting tool that intimately supports the rear surface of the plate part, so that the rear surface of the plate part has an improved flatness at an annular area surrounding the opening of the front plate thereby to increase a sealability between the plate part and the front opening of the housing body.